Abstract

Poster - Splinter General   (Aula 1&2 / virtual plenum)

Photometric Calibration of Astronomical Photp Plates by Gaia SED Fluxes

Maryam Raouph, Prof. Dr. Andreas Schrimpf
Philipps University of Marburg

Background: Time-domain astronomy, the study of the lifetime evolution and changes of cosmic objects, necessitates long-term data collection from various sources. This field focuses on phenomena known as transients, which exhibit significant variability over time. Aim: The objective of this study is to improve the photometric calibration of historic astronomical photo plates, enabling the reliable utilization of the 140-year data contained within these plates. Methods: The idea is to utilize mean low-resolution spectral energy distribution (SED) data from Gaia Data Release 3 (DR3), instead of the color term concept to determine the brightness of sources in the photo plates' color systems. The Gaia DR3 Blue and Red Photometer (BP and RP) provides comprehensive coverage of the full sky down to magnitudes of G < 17.6, spanning the optical to near-infrared wavelength range of 330 to 1050 nm. To handle Gaia BP/RP spectral data effectively, GaiaXPy, a Python library developed by the Gaia archive, is employed. Additionally, photometric calibration is performed using an open-source Python package known as PyPlate. Conclusion: The study develops and tests a significant improvement in the calibration of photometric data from astronomical photographic plates. By enabling the calculation of natural magnitudes of sources within the color system of any photo plate, the new method avoids the problematic color term concepts, thus enhancing the accuracy and reliability of photometric measurements Keywords: Astronomical Photo Plates, Photometry, Gaia SED Catalog